Pre-Filter Particulate Collection Member

ABSTRACT

A pre-filter cloth is provided as designed and specifically adapted for use with the ShopVac®, Craftsman™, Rigid® or other similar style wet or dry vacuum. The pre-filter cloth is formed as a generally rectangular envelope formed of a polyester woven and/or nonwoven fabric felt having a weight of between 6-16 oz. The rectangular envelope forms two generally parallel planar sides separated by a pleated or other type of expandable edge construction and includes an open end that is releasably closed, preferably with a hook and loop fastener arrangement that seals the open end during use, but allows opening to permit egress of collected contents. One planar side form an entry portal circumscribed by a rigid connection flange capable of allowing securement to the hose inlet connection generally available on the inside sidewall of the canister vacuum. The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

RELATED APPLICATIONS

There are no previously filed, nor any co-pending applications, anywhere in the world.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to pre-filter dust bag for use in a wet/dry vacuum cleaner and, more particularly, to a pre-filter membrane adapted for use with an otherwise conventional ShopVac® style wet or dry vacuum.

2. Description of the Related Art

A typical shop vacuum cleaner available in the market does not require a collecting bag for dry pick-up. However, when the shop vacuum's tank is full, it is messy, dusty and a respiratory health hazard to empty it into a disposable plastic bag or a trash container.

There are disposable bags available in the market for shop vacuum cleaners manufactured by ShopVac® Corporation, of Williamsport, Pa., but are only effective with dry, lightweight materials. However, these typically open filter paper bags are designed for dry pick-up of fine dust or particulates, and function merely to collect by gravity the deposition of materials in conjunction with the paper filter. These bags are not suitable to collect large, heavy debris, nor can they pick up a moist material without the likelihood of the bag overflowing and breaking apart within the collection canister.

Therefore, it would be cleaner and more convenient to have an closed, breathable cloth bag inside a canister style vacuum cleaner's tank to collect debris directly into the bag.

Open plastic bag designed to fit a shop vacuum cleaner are available in the market manufactured by Roebuck and Co., of Hoffman Estates, Ill. under the trade name Craftsman™. The Craftsman™ disposable bag is a plastic trash bag, and they are made to fit a specific size of a shop vacuum cleaner's tank. However, the user has to cut a hole on the bag to attach it to the inlet of a shop vacuum cleaner's tank. If the hole is not properly cut, filter clogging by the bag and failure of collecting debris, leaves, and particulates in the bag may result. It is not convenient to use, and there is a need for improvement.

A search of the prior art did not disclose any patents that read directly on the claims of the instant invention; however, the following references were considered related.

U.S. Pat. No. 4,229,193, issued in the name of Miller, discloses a vacuum cleaner filter bag assembly provided for protecting against atmospheric contamination upon removal of the filter bag from a vacuum cleaner. The filter bag assembly includes a primary filter bag, an airtight shield, a secondary filter bag and a tertiary filter. The shield and secondary filter bag are connected so as to define a sealed enclosure within which the primary filter bag is disposed. The primary filter bag has an inlet opening but is otherwise sealed closed. An inlet opening formed in the shield is aligned with the inlet opening of the primary filter bag so that the suction hose of the vacuum cleaner directs air with entrained particulates directly into the primary filter bag. The air which passes through the primary filter bag is next passed through the secondary filter bag. The tertiary filter, which is disposed in the receptacle defined by the bag shape of the secondary filter bag, filters the air which has passed through the secondary filter bag before it is discharged to the atmosphere.

U.S. Pat. No. 6,156,086, issued in the name of Zhang, discloses a vacuum cleaner filer bag including at least two sidewalls which sidewalls are joined by seams. At least one first sidewall comprises a film laminate of a heat sealable film layer and a film support layer. At least one second sidewall comprises a filter laminate comprising at least a synthetic fiber filter layer and synthetic fiber support layer where there is 8 at least one first sidewall is joined to adjacent sidewalls by thermal seams. The filter layer is preferably a high efficiency microfiber filter media which provides HEPA level performance for the vacuum cleaner bag.

U.S. Pat. No. 5,690,710, issued in the name of Stephan, discloses a cloth bag filter formed with a generally cylindrical porous sidewall through which a vacuum is drawn for filtering of contaminant from an air stream, an open upper end for connection to the vacuum source, and a generally closed but optionally porous lower end portion. The sidewall is sufficiently flexible such that it collapses radially inwardly when air is flowing therethrough, simultaneously causing the lower end portion of the bag to be drawn upwardly toward the upper end portion. Upper and lower rings are secured to the upper and lower end portions of the bag for radially supporting the end portions. The weight of the lower ring causes the lower portion of the bag to automatically drop when the vacuum source is turned off, thus causing the sidewall to automatically expand outwardly to a generally vertically hanging position, disrupting the cohesion of the contaminant collected thereon, and causing such contaminant to break-up and fall from the filter.

U.S. Pat. No. 7,341,612, issued in the name of Nhan et al., discloses a disposable open bag for a power tool such as a ShopVac® cleaner has a mounting plate with an opening for receiving debris from the intake of the power tool. The mounting plate is also provided with a vent opening(s), e.g., to prevent the bag from closing in on the air filter and blocking the airflow. The said bag provides a cleaner and more convenient means of collection of the debris, leaves, and particulate matters directly into the bag.

U.S. Pat. No. 6,726,884, issued in the name of Dillon et al., discloses an insulating liner for use with exhaust system or pollution control devices such as catalytic converters and diesel particulate filters or traps. The insulating liner is shown in relation to an end cone for use with a catalytic converter. The end cone includes an outer metallic end cone and a free-standing insulating cone positioned within the outer metallic end cone. A substantial portion of the inner surface of the insulating liner is exposed to hot exhaust gas from an internal combustion engine. The insulating liner is preferably formed of a composite containing inorganic fibers and/or particles, which makes the insulating liner rigid, yet capable of withstanding repeated mechanical and thermal shocks.

U.S. Pat. No. 7,627,928, issued in the name of Crevling, Jr. et al, discloses a vacuum cleaner having a housing defining a blower port, an exhaust port, and a flow path between the blower port and the exhaust port. The vacuum cleaner also includes a removable cap assembly for the blower port to direct discharge airflow via the flow path to the exhaust port. The removable cap assembly, in turn, includes a cap head that engages the blower port to close the blower port, a cap body coupled to the cap head and inserted in the flow path, the cap body comprising a frame through which the discharge airflow passes, and a sound-influencing material supported by the frame within the flow path to reduce noise effected by the discharge airflow. The sound-influencing material may include a reticulated foam roll disposed in the frame to diffuse the discharge airflow.

U.S. Pat. No. 6,565,637, issued in the name of Alberts, Ill. et al., discloses a filter assembly for a vacuum cleaner that includes a main housing having an inlet and an outlet. A motor moves air from the inlet to the outlet, and a first filter is arranged between the inlet and the outlet for filtering the air. An inner wall and an outer wall that is spaced apart from the inner wall form a cavity between the walls. The cavity is located between the first filter and the outlet. The inner wall has an inner opening that permits air to flow from the first filter into the cavity, and the outer wall has an outer opening. A back cover is removably secured to the outer wall over the outer opening to seal the cavity and guide the air from the cavity to the outlet. The back cover includes an access opening that is removably secured to the back cover over the access opening to seal the access opening. A filter cartridge is removably disposed within the cavity. The filter cartridge has a first side with a first opening and a second side opposite the first side and adjacent to the access cover with a second opening. The filter cartridge has a second filter, such as a HEPA filter, disposed therein between the first and the second openings for further filtering the air. A portion of the first side is in sealing engagement with a portion of the inner wall such that the first opening is aligned with the inner opening wherein the motor moves the air from the inner opening to the second opening.

U.S. Patent Application Publication No. 2009/0242469, filed in the name of Calabrese, discloses a filter assembly with an inlet for supplying a fluid to be cleaned and an outlet for returning cleaned fluid. A cloth filter is disposed between the inlet and the outlet. The filter has a web of filter cloth wound on a supply roll and guided along an effective filter area to a takeup roll for receiving clogged filter web. A motor is connected to the takeup roll for rotating the takeup roll and for transporting the filter cloth forward across the effective filter area. A switching device is connected to selectively energize the motor and to index the filter cloth forward by an amount less than a length of the effective filter area.

U.S. Patent Application Publication No. 2008/0196366, filed in the name of Conrad, discloses a surface cleaning apparatus. In some embodiments, the surface cleaning apparatus comprises a member having a dirty fluid inlet. A fluid flow path extends from the dirty fluid inlet to a clean air outlet of the surface cleaning apparatus, and includes a suction motor. At least a first air cleaning unit comprising a cyclonic cleaning stage is positioned in the fluid flow path. A material collection chamber is in flow communication with the at feast one cyclone and is adapted to receive a liner bag. A vacuum line extends between the fluid flow path and an interior of the material collection chamber and is connectable in flow communication with the fluid flow path. A valve is associated with the vacuum line and moveable between a first position in which the vacuum line is open and a second position wherein the line is closed.

U.S. Patent Application Publication No. 2008/0196745, filed in the name of Conrad, discloses a surface cleaning apparatus. In some embodiments, the surface cleaning apparatus comprises a member having a dirty fluid inlet. A fluid flow path extends from the dirty fluid inlet to a clean air outlet of the surface cleaning apparatus and includes a suction motor. At least one cyclone is positioned in the fluid flow path and has at least one material outlet and a divider plate associated with the material outlet. A material collection chamber is in flow communication with the at least one cyclone. The apparatus further comprises a liner bag retaining member.

U.S. Patent Application Publication No. 2008/0302070, filed in the name of Castronovo, discloses a particularly advantageous vacuum cleaner system with at least two filters and self-cleans its filters via back-flushing, without needing to stop normal operation to self-clean. Also, a self-cleaning valve assembly is provided for use in a vacuum cleaner. Also, a vacuum cleaner is provided that uses permanent, self-cleaning filters, and does not need disposable filters or filter bags, and advantageously can use inexpensive plastic bags. In another vacuum cleaner system, waste is collected in an ordinary plastic bag without any special preparation or modification of the bag being needed. Further, an inventive self-cleaning X-valve assembly cleans itself and is useable in the vacuum cleaner system.

U.S. Patent Application Publication No. 2010/0071151, filed in the name of Crevling, Jr. et al., discloses a a vacuum cleaner having a housing defining first and second ports. The vacuum cleaner also includes a cap assembly. The cap assembly includes a cap head to close the first port such that airflow is directed via a flow path to the second port, a sound-influencing material, the sound-influencing material removably held to the cap head and disposed within the flow path to reduce noise effected by the airflow. The flow path is configured to cause the airflow to pass through the sound-influencing material and the flow path to the second port. The sound-influencing material is removable to allow cleaning of the sound-influencing material. The sound-influencing material may include a reticulated foam roll disposed in the frame to diffuse the discharge airflow.

Consequently, a need has been felt for providing an apparatus and method of pre-filtering particulate media in wet or dry applications in a manner that extends the life of the paper cartridge filter in a resealable, washable and resuseable manner.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide art improved to a pre-filter dust bag for use in a wet/dry capable vacuum cleaner.

It is a feature of the present invention to provide an improved pre-filter membrane adapted for use with an otherwise conventional ShopVac®, Craftsman™, Rigid® or other similar style wet or dry vacuum for all types of debris.

Briefly described according to one preferred embodiment of the present invention, a pre-filter cloth is provided as designed and specifically adapted for use with the ShopVac® Model 92L625C filter (or similar design). The pre-filter cloths is formed as a generally rectangular envelope formed of a polyester woven or non-woven felt having a weight of between 6-16 oz. The rectangular envelope forms two generally parallel planar sides separated by a pleated or other type of expandable edge construction and includes an open end that is releasable closed, preferably with a Velcro® type hook and loop fastener arrangement that seals the open end during use, but allows opening to permit egress of collected contents. One planar side form an entry portal circumscribed by a rigid connection flange capable of allowing securement to the hose inlet connection generally available on the inside sidewall of the canister vacuum.

In accordance with a preferred embodiment, the use of a prefilter dust collection member according to the preferred embodiment in conjunction with a canister-type vacuum cleaner will maintain the optimum performance and increase the efficiency of the paper cartridge filter normally provided with such a canister-type vacuum cleaner.

Another preferred embodiment of the present invention allows for various densities and materials of cloth to accommodate different working conditions, such as, for example, a light weight non-woven and/or woven polyester fabric for normal applications, a denser non-woven and/or woven polyester fabric for high particulate environments, or a micro felt or duo density for super high efficiency in removing fine particulates such as drywall dust or in hazardous material applications.

In addition to effective use with large or small particulates, the present invention can further be used in conjunction with liquids or in high-humidity applications.

An advantage of the present invention is that the fabric nonwoven and/or woven material generates a static attraction to collected dirt and particulates, which allows the filtered media to ‘stick’ to the fabric's fibers rather than ‘plugging’ the pores between.

Another advantage of the present invention is that it can be emptied and cleaned, allowing for reuse in a number of applications.

Further, a preferred embodiment of the present invention can allow for the conversion of an otherwise conventional ShopVac®, Craftsman™, Rigid® or other style type device to be adapted for use as a HEPA filter or in HAZMAT conditioner. In conjunction with such cleanup activities, the present invention can be safely and properly discarded, thereby preventing contamination of the vacuum canister itself with its built-in cap on the inlet side of the bag.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:

FIG. 1 a and 1 b are perspective views of a canister type vacuum according to the PRIOR ART, shown as a ShopVac® Mode 92L625C, shown as an upper lid and lower canister, respectively;

FIG. 2 is a front elevational view of a pre-filter particulate collection member according to the preferred embodiment of the present invention;

FIG. 3 is a perspective view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 a is a perspective view of a rigid mounting plate 120 capable of allowing securement of the present invention to the hose inlet connection of a canister type vacuum according to the PRIOR ART;

FIG. 6 b is an alternate embodiment thereof;

FIG. 7 is an exploded perspective view of the mounting plate of FIG. 6 a;

FIG. 8 is a perspective view of the pre-filter collection member according to the preferred embodiment of the present invention, shown installed within a vacuum canister;

FIG. 9-10 are close up view of the open end 106 of the pre-filter collection member according to the preferred embodiment of the present invention, shown sealed and opened, respectively; and

FIG. 11 is a close up detail of the rigid mounting plate 120 shown installed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description, for purposes of explanation, numerous specific details are set forth in order to facilitate thoroughly understanding the methods, systems, and apparatus of a pre-filter dust bag dust membrane bag for use in a wet/dry vacuum cleaner and so on. It may be evident, however, that the methods, systems and so on can be practiced without these specific details. As used in this application, the term “nonwoven” or “nonwoven fabrics” are broadly defined as sheet or web structures bonded together by entangling fiber or filaments (and by perforating films) mechanically, thermally or chemically. They are generally flat, porous sheets that are made directly from separate fibers or from molten plastic or plastic film. They are not made by weaving or knitting and do not require converting the fibers to yarn. Nonwoven fabrics are engineered fabrics that may be a limited life, single-use fabric or a very durable fabric for long life multiple uses. Nonwoven fabrics provide specific functions such as absorbency, liquid repellency, resilience, stretch, softness, strength, flame retardancy, washability, cushioning, filtering, bacterial barrier and sterility. These properties are often combined to create fabrics suited for specific jobs, while achieving a good balance between product use-life and cost. They can mimic the appearance, texture and strength of a woven fabric and can be as bulky as the thickest paddings. In combination with other materials they provide a spectrum of products with diverse properties, and are used alone or as components of apparel, home furnishings, health care, engineering, industrial and consumer goods.

As shown in FIG. 1 a-1 b, a canister type vacuum, generally noted as 10 is shown according to the PRIOR ART. Such a vacuum 10 is shown as a ShopVac® Model 92L625C; however, as would be apparent to a person having ordinary skill in the relevant art, in conjunction with the present teachings and disclosures, the use of such a ShopVac® is shown for exemplary purposes and the present invention can be used in conjunction with any similar or equivalent type of canister type vacuum of various sizes, styles, models, or the like that would include a canister 11 forming a collection receiving chamber 12, an intake element shown as an intake hose 14 in fluid communication with said chamber 12 via an intake portal 16 formed by the canister 11. A motor driven pump or fan 18 accessing the collection receiving chamber 12 is creates an air motive force for drawing fluid through the intake hose 14 and out of a discharge portal 20. A filter medium, generally a paper cartridge element 22 is placed between the intake portal and the discharge portal 20 and forms the separation membrane to allow passage of fluid, usually air, and solid particulates carried within the fluid stream. The canister 12 then thereby collects the separated solids.

The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within the FIGS. 2-11.

1. DETAILED DESCRIPTION OF THE FIGURES

Referring to FIG. 2-5, a pre-filter particulate collection member is provided according to the preferred embodiment of the present invention, for use generally in combination with the canister type vacuum, generally noted as 10 of the PRIOR ART and is formed as a generally rectangular envelope formed of a polyester non-woven and/or woven closed bag 100. The generally rectangular envelope formed of a polyester non-woven and/or woven felt having a weight of between 6-16 oz.

The rectangular envelope 100 forms two generally parallel planar sides, a first planar side 102 separated from a second planar side 102 by a pleated or other type of expandable edge construction 104 and includes an open end 106 that is releasable closed, preferably with a Velcro® type hook and loop fastener arrangement 108 that seals the open end 106 during use, but allows opening to permit egress of collected contents. One planar side 102 forms an entry portal 110 circumscribed by a rigid mounting plate 120 capable of allowing securement to the hose inlet connection.

Referring in greater detail to FIGS. 6 a-7 and 11, the mounting plate 120 is attached to the first planar side 102 circumscribing the entry portal 110 by impingement of a first plate element 122 to a second plate element 124 in a manner such that the first planar side 102 is sandwiched between the two and the woven and/or non-woven fabric. A sealable gasket 126 is also secured between the first plate element 122 and second plate element 124. The first plate element 122 forms a plurality of heat stakes 126 radially disposed about an entry portal access orifice 130. The gasket 126 further forms a similar number of alignment holes 136 corresponding to the number and location of the heat stakes 126. The second plate element 124 similarly forms holes 140 corresponding in number and location with, and designed to received the heat stakes 126. In an alternate embodiment, shown in FIG. 6 b, a locking cap 138 is attached to the first plate element 122, and a protruding sealing ring 139 is formed about the access orifice 130 on the second plate element 124 such as to form a closeable connection there between. When the cap 138 is attached to mounting plate 120 after releasing the bag from the inlet 110, the contents are sealed to prevent dust and debris from escaping the bag.

The first plate element 122 and second plate element 124 can be attached by any known methods in the art, such as adhesive, thermal bonding, ultrasonic bonding, sonic welding, cohesive melting, or the like. The attached and affixed mounting plate 120 can be attached to the mounting bracket inside of the vacuum canister. The mounting plate 120 is provided with an opening 110, through which air and entrained debris enter the bag 100 from the shop vacuum cleaner inlet (intake). The function of the mounting plate 120 is to facilitate the ease of bag installation and to securely hold the bag 100 to the inlet 11 during vacuum operation.

The diameter of the opening 110 is preferably larger than the outside diameter of the shop vacuum cleaner inlet 11. The gasket 126 is then preferably larger than the outside diameter of the shop vacuum cleaner inlet 11, and thereby forms a sealing engagement thereto. This allows a tight fit of the mounting plate 120 on the inlet 11. Thus, it secures the mounting plate 120 on the inlet 11.

The mounting plate 4 is preferably made of a rigid material, such as a plastic material. It has been found that the use of cardboard is insufficient in structural rigidity.

The open end 106 is shown in greater detail in conjunction with FIG. 9-10. A first loop fastener element 150 is affixed laterally across the first planar side 102 at a first distance from the terminal end of the open end 106. A first hook fastener element 160 is similarly affixed laterally across the second planar side 104, at a second distance between the terminal end of the open end 106 and the first distance of the loop fastener element 150. In this construction design that the open end 106 can be placed together and rolled such that the loop fastener element 160 meets and mates with the hook fastener element 150 in a manner that forms a folded seam 170 to thereby seal the open end 106 in a manner that seals the open end 106 during use, but allows opening to permit egress of collected contents. The hook and loop mechanical fasteners can be affixed to the appropriate planar sides with an adhesive backing or by sewing the elements directly to the planar sides.

The filter bag 110 itself is anticipated as being available in various sizes as well as different densities and materials of cloth to accommodate different working conditions. For example, a lightweight polyester fabric of between 6-12 oz. densities is anticipated for normal applications, while a denser polyester fabric, such as a 16 oz felt bag, would be more suited for high particulate environments. Further still, various kinds of super high efficiency material can be used in removing fine particulates or in hazardous material applications.

2. OPERATION OF THE PREFERRED EMBODIMENT

To use the present invention in accordance with a preferred embodiment of the present invention, the user first removes the vacuum motor lid assembly from the shop vacuum cleaner and inserts a pre-filter particulate collection member according to the preferred embodiment of the present invention into the tank, wrapping the length of the envelope about the outer sidewall of the vacuum motor lid assembly is then mounted back.

During a vacuum operation, the motor of the shop vacuum cleaner removing air from the interior of the tank, creating a pressure drop (vacuum) within the tank. Air and entrained debris are drawn into the through the hose, and inlet, through the pre-filter collection membrane and into the tank. Particulates are collected inside the bag, with fluid (air) permeating through the envelope sidewalls. When the bag is full, the user removes the vacuum motor lid assembly from the shop vacuum cleaner and removes the bag from the tank. The bag can then be disposed, or emptied, washed out (cleaned if desired) and reused.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. Therefore, the scope of the invention is to be limited only by the following claims. 

1. A pre-filter membrane adapted for use with an otherwise conventional ShopVac® style wet or dry vacuum comprising: a collection envelope having a first planar side separated from a second planar side by an expandable edge construction, and further forming an open end, said envelope formed of a woven and/or nonwoven fabric; a hook and loop fastener arrangement for sealing said open end during use, but for allowing opening to permit egress of collected contents; an entry portal formed on one planar side; a rigid mounting plate circumscribing said entry portal, said mounting plate adapted to allow for securement to a hose inlet connection of the type generally available on an inside sidewall of a commercially available canister vacuum; wherein a sealed folded seam is formed by said hook and loop fastener thereby seal the open end in a manner that seals the open end during use, but allows opening to permit egress of collected contents.
 2. The pre-filter membrane of claim 1, wherein said mounting plate comprises: a first plate element; a second plate element; a sealable gasket; wherein said first planar side is impinged between said first plate element and said second plate element, with said sealable gasket further sandwiched there between that and the woven and/or nonwoven fabric, thereby forming a connection of said mounting plate to said first planar side.
 3. The pre-filter membrane of claim 2, wherein said first plate element forms a plurality of heat stakes radially disposed about an entry portal access orifice that corresponds in number and location with holes formed by said second plate element for receiving the heat stakes.
 4. The pre-filter membrane of claim 1, wherein: a first loop fastener element is affixed laterally across the first planar side at a first distance from the terminal end of the open end; a first hook fastener element is affixed laterally across the second planar side at a second distance between the terminal end of the open end and the first distance of the loop fastener element; wherein when said open end is placed together and rolled such that the loop fastener element meets and mates with the hook fastener element.
 5. The pre-filter membrane of claim 4, said filter bag is formed of a lightweight polyester fabric of between 6-16 oz. densities.
 6. The pre-filter membrane of claim 4, said filter bag is formed of micro felt super high efficiency material.
 7. The pre-filter membrane of claim 2, wherein said mounting plate further comprises a sealable cap for closing said entry portal. 